Burglar alarm



United States Patent O 9 Claims ABSTRACT OF THE DISCLOSURE A burglar alarm comprising an elongated housing h'aving a bottom wall, -a pair of upturned side walls andan upturned end wall, such end wall including a slot therein. A pivotal cartridge holder is formed with an upwardly Opening cartridge-receiving socket proximate the end of the housing opposite the end of wall and a transverse bore intermediate the ends of the housing. A mounting pivot extends through the bore and is supported from the side walls. A swingable hammer is former with a transverse bore for receiving the pivot, a tiring pin spaced the same radial distance from the pivot as the socket and adapted to engage a cartridge held in the socket and further being formed with a latching lip disposed near its free end. A spring biases the hammer around the pivot to engage the tiring pin with a cartridge held in the socket. A keeper holds the hammer in its cocked position and includes an elongated slide portion extending through the end wall slot, a bridging portion disposed outside of the end wall extending upwardly from the notch and a turned back lip for engaging the hammer lip. A spring element interconnects the keeper and cartridge holder to maintain the keeper biased into locking engagement with the lip of the hammer and the cartridge holder biased downwardly.

BACKGROUND OF INVENTION Field of invention The present invention relates to a burglar alarm having means for tiring a cartridge as a warning.

Description of prior art Presently known burglar alarms for tiring cartridges are comparatively expensive to manufacture and some utilize the movement of the opening door to cock the hammer thereby resiliently resisting opening of the door and raising the possibility of notifying the unwanted intruder that a burglar alarm will be fired by further opening of such door. Other cartridge-tiring burglar alarms do not provide for positively locking the hammer in its cocked position and may inadvertently be tired giving a warning of unwanted intrusion when, in fact, there is no such intrusion.

SUMMARY OF INVENTION It is a particular object of the present invention to provide a cartridge ring burglar alarm comprised of an elongated housing including a pair of side walls and an end wall, such end wall being formed with a slot. An elongated cartridge holder is formed with an upright upwardly opening cartridge-receiving socket proximate the end of the housing opposite the end wall and a transverse bore intermediate the housing ends. A pivot pin extends through the bore and is supported from the side walls. A swingable elongated hammer is carried pivotally on one end by the pivot pin and such hammer is formed with a ring pin disposed substantially the same radial distance from the pivot as the socket and is adapted to engage a cartridge held in the socket. The hammer is further formed with a latching lip disposed near its free end. A

3,429,292 Patented Feb. 25, 1969 spring is provided for biasing the hammer around the pivot to engage the tiring pin with a cartridge held in the socket. A keeper is provided for maintaining the hammer in its cocked position and includes a slider portion extending outwardly through the slot, a bridging portion disposed outside of the end wall and projecting upwardly, and a turned back lip for engaging the hammer lip. A spring element interconnects the keeper and cartridge holder to bias the keeper lip into engagement with the cocked hammer and for biasing the cartridge holder downwardly.

DESCRIPTION OF DRAWING FIG. l is a broken perspective view of a house door and Awall upon which is mounted -a preferred form of burglar alarm embodying the present invention;

FIG. 2 is a horizontal sectional view, in enlarged scale, taken along the lines 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view taken along'the lines 3-3 0f FIG. 2;

FIG. 4 is a bottom view, in reduced scale, of the burglar alarm in FIG. 1;

FIG. 5 is a front view of the burglar alarm shown in FIG. 4; and

FIG. 6 is a partial vertical sectional view, in enlarged scale, taken along the lines 6-6 of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1, a preferred form of burglar alarm A embodying the present invention is mounted on a wall W and connected with a door D by a connecting chain 11. The burglar alarm A includes a housing, generally designated 13, which mounts a pivotal cartridge holder, generally designated 15, which mounts a pivotal cartridge holder, generally designated 15, and a swingable hammer, generallyl designated 17. Referring to FIG. 3, the hammer 17 is maintained in its cocked solid outline position, by a keeper 18 which is slidable outwardly to the right to release the hammer from its solid outline position to its dotted outline position.

Referring to FIGS. 2 and 3, the housing 13 is conveniently made of sheet metal and is formed with a horielongated strip of sheet metal which is turned back on itself at a point 31 intermediate its ends, the turned back portions extending adjacent one another for a short distance and then bending outwardly away from one another and curving back together to form opposite halves of a cylindrically shaped cartridge socket 35. Inwardly of the socket 35 the halves of the sheet metal strip dening the holder 17 extend adjacent one another for a short distance and then flare outwardly and extend parallelof one another to form opposite legs 37 of a yoke. The extremities of the legs 37 are formed with a transverse bore 41 for receiving a horizontal rivet 43 supported from the side walls 21 and 23.

The inner end of the hammer 17 is received between the legs 37 and includes a transverse bore for receiving the rivet 43. Referring to FIGS. 2 and 3, the intermediate portion of the hammer 17 is formed with an initially upwardly extending pointed firing pin 47 which is spaced the same distance from the rivet 43 as the socket 35. The side of the hammer 17 opposite the tiring pin 47 is formed with an outwardly projecting latching lip 51 which is en gaged by a cooperating lip 53 formed on the free end of the keeper 18. A handle 55 projects outwardly beyond 3 the lip 51 and also beyond the end wall 25 when the hammer 17 is rotated to its right-hand position (FIG. 3).

A generally U-shaped catapult spring of the torsion type and generally designated 59 is formed with a continuous piece of spring wire. The wire forming the spring 59 is turned back on itself to form a bale portion 61 intermediate its ends which underlies the hammer 17 when it is in its cocked right-hand position. The longitudinal returns 63 from the bale portion 61 extend adjacent the side walls 21 and 23 and are bent around the rivet 43 at 65 and ride on inwardly dented bosses 67, formed in the side walls 21 and 23, and then project back under the bale 61 to define rockers 69 abutting the bottom wall 19 of housing 13. The extremities of the spring 59 project through a pair of relatively small slits 71 formed in the end wall 25 and then turn upwardly to form retainer portions 73.

The keeper 18 has its inner extremity formed with a relatively wide spacer body 77 that substantially spans the space between the bottom wall 19 and the ends of the holder and hammer 17 which are connected to the rivet 43. The outer end of the keeper 18 is generally C- shaped and includes a relatively narrow slide portion 81, a vertically extending bridge portion 83, and the aforementioned return lip 53. The slide portion 81 extends outwardly through a slot 89 formed centrally in and at the lower end of the end wall 25. The return lip 53 extends through an open-ended notch 91 formed centrally in the upper extremity of the wall 25. Outward movement of the keeper 18 is limited by a vertical shoulder 93 which extends above the top edge of the slot 89 and forms a stop that abuts the inner surface of the end wall 25. An upwardly and inwardly-facing wedge surface 95 is formed by the return lip 53, such surface being engaged by a cooperating downwardly and outwardly facing wedge surface 97 formed below the hammer lip 51 whereby downward movement of the hammer 17 will cam the keeper 18 to the right (FIG. 3) to enable the hammer lip 51 t0 be engaged below the return lip 53.

Referring to FIG. 4 of the housing 13, the slide-receiving notch 89 in addition to extending vertically in the wall for receiving the slide 81, preferably projects a sufficient length along the bottom wall 19 to enable the spacer body 77 of the keeper to be installed therethrough. With this arrangement, the keeper 18 can be inserted upwardly through the slot 89 and yrotated into its horizontal position, as shown in FIG. 3, before the rivet 43 is inserted and when such rivet is installed the spacer 77 cannot be elevated and the keeper 18 is kept captive.

Referring to FIG. 3, a tension spring 101 interconnects the inner end of the keeper 18 and the intermediate portion of the holder 15, one end of such spring being hooked to a transverse bore 1 03 formed in the keeper 18 and the other end thereof being hooked into a like transverse bore 105 formed in an ear 107 depending from the intermediate portion of the holder 15. With this arrangement, the keeper 18 is normally biased into its inner position of FIG. 3 with the lip 53 engaged with the lip 51 of the cocked hammer 17 and the holder 15 is biased downwardly against the top edge 109 of the housing end wall 27.

Still referring to FIGS. 2 and 3, the back side wall 21 of the housing includes a mounting ear 111 projecting outwardly beyond the end wall 27 and having a bore for receiving a mounting screw 113. The wall 21 also includes a second mounting bore near the wall 25 for receiving a second mounting screw 115. An access bore 117 is included in the front wall 23 in alignment with the head of the mounting screw 115.

Referring to FIGS. 1, 3, and 6, the triggering chain 11 has its one end link 121 hooked through a bore 123 in the bridge portion 83 of keeper 18 and has its opposite end link 125 received to a fastener, generally designated 127. The fastener 127 is formed with a pair of legs 128 and 129, the leg 128 being bent laterally and looped back on itself to form a hook 131 for receiving the free ex- 4 tremity of the straight leg 129. The straight leg 129 extends through a bore 135 formed in a mounting bracket 137 secured to the door D.

The burglar alarm A is installed, as shown in FIG. 1, 'by inserting the mounting screws 113 and 115 through their respective bores and screwing them into the wall W. The triggering chain 11 is then fastened to the mounting bracket 137 by means of the fastener 127. It will be clear that the door D and wall W are used as illustrative examples since the alarm A can be used between any two relatively moving members, such as in the case of windows and frames. A cartridge 141, such as the primer for a shotgun shell, is inserted in the holder 15. Since the holder 15 is pivotable upwardly on the rivet 43 itcan be raised for convenient insertion of the cartridge 141. When the raised holder 15 is released after insertion of the cartridge 141 it will be rotated downwardly by the spring 101 to bring the bottom edge of its outer portion into abutment with the top edge 109 of the end wall 27. Cocking of the hammer 17 is 'accomplished Iby grasping the protruding handle 55 and rotating the hammer to the right, in a clockwise direction, as viewed in FIG. 3. Sliding engagement between the wedged surfaces 97 and 95 will force the keeper 18 outwardly to enable the hammer lip 51 to pass the keeper lip 53 and the tension spring 101 will bias the keeper to the left to maintain the keeper lip 53 engaged above the hammer lip 51 thus retaining the hammer 17 in its cocked position.

With the burglar alarm A so prepared, when an intruder opens the door D, swinging it inwardly toward the viewer, as viewed in FIG. 1, the firing chain 11 will tighten and pull the keeper 18 to the right, as shown in broken lines in FIG. 3. Such movement of the keeper 18 will disengage the keeper lip 53 from the hammer lip 51, freeing the hammer 17 to be catapulted counterclock- Wise around the pivot 43 by the spring 59, as shown in phantom outline in FIG. 3. Such catapulting of the hammer 17 will drive it forcefully around the rivet 43 and bring the firing pin 47 into firing engagement with the top surface of the cartridge 141 thus detonating the included charge. Referring to FIG. 6, continued opening of the door D will cause the triggering chain 11 to apply a greater force to the bottom end of the fastener 127 and result in the hook 131 being sprung upwardly over the end of the straight leg 129 by the bracket 137 thus freeing the door D for full opening without damage to the alarm A or wall W.

From the foregoing it will be apparent that the burlgar alarm of this invention is economical to manufacture and in stall and that it is foolproof in use. The hammer is convenient to cock and by utilizing the fastener 127 there is no danger of pulling the alarm from its mounted position on the wall W.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. A burglar alarm for firing a cartridge comprising: an elongated housing including a pair of side walls, and irst and second end walls, a horizontal pivot means mounted medially and transverse of said side walls adjacent the upper edge thereof, an elongated cartridge holder formed with an upright upwardly-opening cartridge-receiving socket, one end of said holder being pivotally mounted on said pivot means the other end of said holder opposite said pivot means bearing on said first end wall, a swingable elongated hammer means having one end pivotally supported on said pivot means and extending oppositely to said holder and having a -free end portion normally disposed over said second end wall, a firing pin integrally formed with said hammer means and disposed on substantially the same radius with respect to said pivot means as said socket and adapted to engage a cartridge held in said socket, a latching lip formed integrally with said hammer means and disposed adjacent said second end Wall, rst spring means operatively associated with said pivot means and said hammer means biasing said hammer means about said pivot means to engage said firing pin with a cartridge held in said socket, an elongated keeper means horizontally slidably disposed in said housing and formed at one end with a substantially reversed C-shaped portion, an aperture means in said second end wall accommodating a portion of the reversed C-shaped portion for slidable movement of said C-shaped portion exteriorly of said housing, said C-shaped portion having a free end portion terminating in a complementary locking means, said locking means being engageable with said locking lip to releasably lock said hammer means from rotation towards said socket and said locking means being disengageable therefrom upon outward sliding movement of said keeper means, second spring means interconnecting said keeper means and said cartridge holder to bias said locking means into engagemerit with said hammer lip when said hammer means is in its cocked position and simultaneously biasing said end portion of said cartridge holder downwardly on said irst end wall.

2. A burglar alarm as set forth in claim 1 wherein said hammer means includes a handle projecting outwardly beyond said lip.

3. A burglar alarm as set forth in claim 1 wherein said aperture is elongated in one direction and wherein said slide portion is complementally elongated to maintain said keeper in an upright position.

4. A burglar alarm as set forth in claim 1 wherein said end second wall includes a second notch for projection inwardly therethrough of said locking means.

5. A burglar alarm as set forth in claim 1 wherein said keeper includes a stop for abutting said end wall to limit sliding movement of said keeper.

6. A burglar alarm as set forth in claim 1 wherein said locking means includes an upwardly and inwardly facing wedge surface for engagement by said hammer means upon rotation of said hammer means into cooking position whereby said locking means will be moved Outwardly to clear said hammer lip.

7. A burglar alarm as set forth in claim 1 wherein said hammer lip includes a wedge surface which faces outwardly and downwardly when said hammer is rotating into its cocked position, such wedge surface being adapted for engaging said locking means to drive it outwardly upon rotation of said hammer into its cocked position to thereby enable said hammer lip to clear Said locking means.

8. A burglar alarm as set forth in claim 1 wherein said housing includes a bottom wall end wherein said pivot pin supports the connected ends of said hammer and cartridge holder spaced above said bottom Wall, said keeper includes a spacer portion which extends into the space between said connected ends of said holder and hammer and said bottom wall, said keeper includes a stop for abutting said end second wall to suiciently limit outward movement of said keeper such that said spacer portion cannot be slid out from under said connected ends, said aperture means extends from said second end wall and a suflicient distance along said bottom wall whereby said spacer portion may be inserted therethrough.

9. A burglar alarm as set forth in claim 1 that includes a triggering member connected on an end to said keeper and including a fastening member on its opposite end, said fastening member including a pair of legs which are connected together at one end, the free end of one leg being formed with a transverse extending backwardly opening loop and the other leg being of suicient length to have its extremity engaged by said loop, said loop being of suicient resiliency to be bent outwardly suiciently by a predetermined amount of force to free said extremity from said hook.

References Cited UNITED STATES PATENTS 707,513 8/ 1902 Howard 116-87 819,914 5/1906 Neff 116-87 1,050,637 1/1913 Fyfe 116-87 FOREIGN PATENTS 21,194 1899 Great Britain.

LOUIS I. CAPOZI, Primary Examiner. 

